Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes

The semiempirical molecular orbital CNDO/S-CI spectral parameterization has been used to elucidate the lower electronic states of a series of dioxodiazacycloalkanes. The a1, b1, and a' oc-cupied molecular orbitals lie predominantly on the oxygen, while a2,b2, and a are largerly nonbonding orbit...

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Publicado: 1981
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09320784_v36_n5_p494_Grinberg
http://hdl.handle.net/20.500.12110/paper_09320784_v36_n5_p494_Grinberg
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_09320784_v36_n5_p494_Grinberg
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spelling paper:paper_09320784_v36_n5_p494_Grinberg2023-06-08T15:53:10Z Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes The semiempirical molecular orbital CNDO/S-CI spectral parameterization has been used to elucidate the lower electronic states of a series of dioxodiazacycloalkanes. The a1, b1, and a' oc-cupied molecular orbitals lie predominantly on the oxygen, while a2,b2, and a are largerly nonbonding orbitals delocalized on the nitrogen and oxygen atoms. The two lowest unoccupied virtual orbitals are predicted to be of b2, a2, and a symmetry. These orbitals are strongly localized on the C = 0 group. The resulting 1 B2(no π*) and 1 A2(n0 π*) spectroscopic states involve intra-molecular charge transfer from the oxygen to the carbon atom of the carbonyl group, which is supported by electron density calculations of these excited states. Although the calculated transition energies may not allow for absolute comparisons with experimental values, it appears that the introduction of self-consistency together with solvation energy and configuration interaction, when the elements of the interaction matrix are properly evaluated, lead to a fairly good Interpretation of the singlet-singlet transitions. The lowest energy singlet excited state calculated for each structure is comprised almost entirely of the nn* configuration. © 1981, Walter de Gruyter. All rights reserved. 1981 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09320784_v36_n5_p494_Grinberg http://hdl.handle.net/20.500.12110/paper_09320784_v36_n5_p494_Grinberg
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description The semiempirical molecular orbital CNDO/S-CI spectral parameterization has been used to elucidate the lower electronic states of a series of dioxodiazacycloalkanes. The a1, b1, and a' oc-cupied molecular orbitals lie predominantly on the oxygen, while a2,b2, and a are largerly nonbonding orbitals delocalized on the nitrogen and oxygen atoms. The two lowest unoccupied virtual orbitals are predicted to be of b2, a2, and a symmetry. These orbitals are strongly localized on the C = 0 group. The resulting 1 B2(no π*) and 1 A2(n0 π*) spectroscopic states involve intra-molecular charge transfer from the oxygen to the carbon atom of the carbonyl group, which is supported by electron density calculations of these excited states. Although the calculated transition energies may not allow for absolute comparisons with experimental values, it appears that the introduction of self-consistency together with solvation energy and configuration interaction, when the elements of the interaction matrix are properly evaluated, lead to a fairly good Interpretation of the singlet-singlet transitions. The lowest energy singlet excited state calculated for each structure is comprised almost entirely of the nn* configuration. © 1981, Walter de Gruyter. All rights reserved.
title Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes
spellingShingle Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes
title_short Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes
title_full Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes
title_fullStr Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes
title_full_unstemmed Molecular Orbital Theory of the Electronic Structure of Organic Compounds III. A CNDO/S-CI SCF MO Study on the Lower Electronic States o! Large Molecules. Singlet-Singlet Transitions of Dioxodiazacycloalkanes
title_sort molecular orbital theory of the electronic structure of organic compounds iii. a cndo/s-ci scf mo study on the lower electronic states o! large molecules. singlet-singlet transitions of dioxodiazacycloalkanes
publishDate 1981
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09320784_v36_n5_p494_Grinberg
http://hdl.handle.net/20.500.12110/paper_09320784_v36_n5_p494_Grinberg
_version_ 1768542371076636672

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